Hi there. I use an old EF Johnson edge wound roller inductor in my home brew 3cx1200 amp. I have forgotten the best lubricant to use for the sliding contacts on it. Any suggestions? Thank you, Paul W
I would like to thank all the kind people who responded to my question regarding the best lubricant for sliding contacts in an old EF Johnson edge-wound roller inductor. Molybdenum disulfide is the o
Hi Rich. Here are some comparative resistivities. As you will see, MoS2 is the semi-conductor range. Values were obtained from Carmichael, R. S. ed., Handbook of Physical Properties of Rocks for the
Hello Richard. I am in the midst of doing the same thing here. I have spent a lot of time trying to find the optimum combination of factors to give the best overall efficiency for the antenna system.
Hi Gerald et al, Just a little reminder: When testing ceramic type tubes and vacuum components with your high-pot tester: ALWAYS ALWAYS ALWAYS clean the ceramic insulator with a degreaser product lik
Actually, Formula 409 was specifically recommended to me by a very long-time employee of ITT-Jennings in their product testing department. This is what she uses everyday in Jennings' testing area. Pu
Hi Dennis. Dishwashing can leave surfactants and or fragrances behind on your components when done. The hardness of water can also leave trace inorganic reside on the device substrate, as well. Washi
This massage was bounced originally due to an outlaw email masseuse accountant submission. Hi group. I am sorry, but I can't stand it any longer! There is virtually NO difference between "D.I." and d
Hi Barry. I built a homebrew hi pot tester using an Emco DC-DC converter that runs 2.5 KV up to about 25 KV. I have tested a lot of vacuum components used in amplifiers and tuners. 1.) It is ESSENTIA
Hi there. Shortly before ramming my SUV into two large elk while mobiling during the WA state salmon run last month, I observed something a bit odd with my trusty old Metron amplifier. While fine tun
Thanks for the input on my Metron amp. Primary suspect is now a ground loop effect. There were absolutely no loose or questionable coax connections, but plenty of potential ground loop paths. There i
Hi John, When it comes to testing HV circuits, there is only one safe approach. Volunteer to teach ham radio to a local elementary school. Once you have a few budding ham candidates, pick the most ir
Hi Jim, Make sure the DUT has been properly degreased before deciding it has failed the hipot test. Finger grease residue on the 8877's ceramic can easily allow 40 microamps to flow externally at 400
Dear Amplifier Group, Another possible approach that could be used to control or almost eliminate the noise generated by air cooling an amplifier is to eliminate air as the working fluid used to tran
Hi Alex, I ran a full length 160 dipole at less than nominal height for many years at my old QTH. I fed my dipole (up at 100 feet suspended between Douglas Fir trees on a mountain about 1000 feet abo
Dear Colleagues, I built a hi-pot tester about five years ago using components purchased from a company called: http://www.emcohighvoltage.com/ They manufacture a wide range of solid state "cubes" an
One of the nice features about the Emco-based high pot tester I built is it requires only a simple fixed 12 VDC input. The variable voltage for the output is controlled internally in the "cube" with